Apparatus for grinding crank shafts



vMm'ch 17, 1925 L. KELLENBERGER APPARATUS FOR GRINDING CRANK SHAFTS Filed June 29, 1925 stud to be Patented Mar, 17, 1925.

UNITED STATES PATE NToF-FicE.

APPARATUS FOR GRINDING vCRAN'K SHAFTS. p

l Application filed June 2a, 1923. seriai No. 648,574.

To all 'whom t may concern:

Be it known that I, LEONHARD KELLEN- BERGER, a citizen of the Republic of Switzerof St. Gallen, in the vCan- Switzerland, have inventland, and resident ton of St. Gallen,

ed certain new and useful Improvements 1n Apparatus for Grinding Crank Shafts, of which the following is a specification.

The present invention relates to an improved apparatus for grinding crank-shafts. Thegrinding thereof is effected by means of comparatively small grinding-wheels which by the aid of a pivoted supporting arm are adapted to be introduced between the crank-webs. Though it has been previously proposed to construct such apparatus, they all have the drawback that their width is too great to permit of the grinding of row cranks, and since the bearing surfaces of the crank-shafts of up-to-date small motors are small, the width of the grinding apparatus of the kind described must of necessity be as small as possible. It is'certainly old in known grinding apparatus to mount belting or other driving-gear between and centrally of two grinding-wheels, yet, in order that the latter have sul'licient grinding power it is essential that the driving belt is of a certain width with the consequent' disadvantage, however, that the smallest possible width of the crank-pin or ground is lcomparatively large. There areother known grinding devices provided with one grinding-wheel only and with a drivingbelt mounted adjacent thereto, the drawback of these devices being'that p upon the tilting vover of the grinding- .55 `paratus;

wheel the belt requires to be detached 'and the wheel removed from the pin.

y invention has for its objectv an improved method and apparatus which makes it possible by means of two grinding-wheels to grind even very short crank-studs, the mounting of the said wheels beingsuch as to require a minimumof room. The'accompanying drawings illustrate one form in which the invention may be embodied, the grindingapparatus in this case being shown as mounted on a lathe and adapted to be driven by the usual gear. It will be lunderstood, however, that' the apparatus could also be'constructed to form an independent machine. In the said drawings Fig.' lv shows a plan of the grinding apthe pins of very small or narl pulleys hereby being 2'is a side view, and i l Fig. 3 a front lview thereof.

Fig. 4 represents-a sectional view of the` supporting and bearing parts;y f

Fig. 5 is a viewsimilar to that in Fig. 2 but with the several lparts in different positions, and

Fig. 6 shows a modiiication of the mountof of thetwo gringing-wheels.

,ieferring to these drawings, a denotes the upperand left-hand grinding-wheel ando the lower right-hand These wheels are arranged close to each other'but not on the same axle. Theoretically they could also be mounted vsideby side, in such a way, that they take upa grinding-wheel.

width approximately double that of one of 3 the wheels, though vin practice it wouldV then be'necessary to leave some small space between them; or, the two wheels mounted apart and so that their ina plane. Journaled close'to the upper and left-hand grinding-wheel a, on a commonI axle therewith, isa grooved'pulley c and similarly mounted relative the grinding-wheel' isa grooved pulley rangement of the two wheels and the two j such, that the pulley of one of the grinding-wheels is loca-ted atthe rear of the other edges are the grinding-wheel a. Provision is further,

made of asupporting arm' e for the grinding-wheels and pulleys, 4this arm beinfr pivoted asshown at f, Figs. 2 and 5.

d, the arcould be grinding-wheel, while; the latter is rearwards of the other pulley, Fig.

belt or driving cord z' led over the pulleys e and d lies slightly ofi' the centre line of the arm e, Fig. 4, r the purpose ofy neutralizing the'pressure or strain on the 'grinding-v wheel. The bending strain ofthe arm e is therefore wholly or nearly eliminated.

Owing to the arrangement crosswise of the two grinding-wheels anclthe two pulleys respectively, the considerable advantage is gained that the driving'cord i is ldriving one of the grinding-wheels only, the other wheel running loosely. The construction. de-

scribed is moreover such as to permit ofthe working alternatively the grinding-wheels a and br 11o ,j of one or the otherpof p Y about by l vor levers, or by afraising rvalso be effected byv 'back to the ple device itis possible to actuate both the grinding-wheels.

'sition, Fig. '5, and thecther To this Vend each f grindingfwheel may either be journaled in 'aV support" or made adjustable in a straight line, or both grinding-wheels may, as previously mentioned and as illustrated in'Fig. 2, vbe made to bear in a pivoted arin e. and so `Vthat they are always exactly at the same distance r' from the pivot rlhe latter may be fixed in anyL suitable way, for instance in a slotted pla-te which, in turn, is mounted on ythe slide-rest of the lathe. Thus,.i the arm @is swung into the position, Fig. 2, the wheel a vis in working position, while upon vthe swinging over ci; the `arm e into thefposition, Fig. 5, the other grinding-Wheel 'b is in working position. l l

f The adjustment of the ar-m yc is brought means off a ,spindle g and by the clamping` tast of a screw it with handle. The adjustment may, however, be effected vby any other suitable and known mechanism, Afor instance by and lowering de- -vice `with stopping means. l The rotation of 'the two grinding-wheels can, of course, two separate'belts .or cords, but vaccording to the preferred construction the two grinding-wheels are actuated by the single driving cord z', is yitself driven by a larger sized grooved .pulley 7c, adjacentto which are ymounted a 'loose and a fast pulley Zr and'm. The pulley movement from the movement by means 10,4, receiving its rotary pulley Z, transmits such of the cord c' and an intermediate roller nv to the pulley c, whence the corda' is led over a guiding roller mounted at 0.l The latter is arranged obliquely in such a manner, Fig. 3, that the said vcord runs from the pulley cV in a slanting direction over to the Lother pulley d. From-there the cord is led larger pullev k.' By this simf In operation Vthe apparatus works as tollirst by the grinding-wheel a, .the same is brought intothe positionfF-ig. 2, yand one .half of the .crank-stud caused tobe ground.

The arm e and consequently the grindingwheel vb Aare thereafter adj-*usted intothe p0- half of `.the

crank-stud ground.-

-`:pulleysA k, land fmfmay l to be `'capable of adjustment eccentrically of rthe 4supporting :and bearing parts .fgrindifngfwheels, it will lbe* :seen that the pulleysadjacent thereto/.each vcomprise two vAnd in orderto :allow thecord c' .to be tightened, the guiding vroller at o .may vbe madev adjustable, or, as an: alternative, the bemounted so as the pivot v f. u h

ireug 'From4 Fig. 4, illustrating section 'for .the

y fparts, thefpartk vI? 'Jbeing the form of a flanged disc "wlith' a fcentraluapim rnzhile g the aid of eccentrics, cams,

vwise of veach otherV which y crank-shafts of two designates a guide-ring fitted on the end of the said pin and serving as a means to prevent ,the detachment of the bearing on the one hand and, .conjointly with the flanged 'part p, forming the grooved pulley for the cord .7l-.on the other. hand. Mounted between Y) may also be oblijqnely-mountedhon thelarm ev as illustrated diagrammatically .in Eig, Y6, the lpurpose of this arrangement ,belli-g -to facilitate the grinding of `@he rounded ofi' ends ofthe crank-stud.. j v v l/Vhat I claim as new and desire tosecure by Letters Patent is n o l. In the herein-described appara-tus applicable lto lathes and other machine 4`tools and adapted `for grinding the 'crank-.studs of crank-shafts, .the combination, with an arm Jpivota'lly mounted Qn the slide-rest of the lathe, of two rotatable rgrindirig-wlneels journaled in the 'tree end ofthe-said pi-vf oted -armand mounted laterally and crossyadriving pulley adjacent :to each of the grinding-wheels and secured ,to fits ',aXle, each .of the driving pulleys beinginfa plane with ythe opposite grinding-.Wheel vand corresponding witgh its Width, and means .to-rotate `the said pulleys and .grinding-wheels.,

2. In the 'herein-described apparatus aprplicable to lathes -and otherl machine toolsv and adapted, 'for .sfDdingrank-,Shafts and more particularly the da k-studs thereof, the combination, with an mounted on the the free end of the said -pivcted arm Yand mounted laterally `and crosswise .ef each 'other and onseparate axles, ley adjacent to eachl ,of the grinding-:wheels and secured to its axle, .veachaoitlzl ySaid y pulleys and grinding-wheels bilg at vthe `same distance 'rom'the pivot-i` ythe arm;

means to rotate the pulleys and Vgrinding wheels;v and mechanisml -gfonfswin-girig fthe arm aboutits piVQtxrto cause the igrindi;ig

wheels to be alternatelybneught into work# Ving position.

8. The combination, tin the therein-:de-

a grocved puland on separate axles, f

arm -pivotally slidefrest oi the lathe, of two rotatable grinding-wheels jouiaialed in scribed apparatus applicablefto lathes and i adaptedffor grinding vthe cranlstudsl-oi `grinding Wheels mountedy laterally' and crosswise .of ,eachl other lon 4separate axles; ta groovedpulleyv adjacent to-.each grinding-wheeland .secured to its axle, each ofthesaid'pirlleysileeingin a plane with the opposite grindinge-wheel ,and corresponding with itswv'dth, andeach ypulley comprising twlo parte, namely', a

flanged discwith Ja'centralf pin, and aguidering litted onthe.- end .othe pin; afdriving cord leading over and between'fthellange 0f the dise and the guide-ring; an arm pivotally mounted on the slide-rest of the lathe and also arranged between the said flange and the guide-ring and forming a bearing Q for the aforesaid central pin and pulleys and grinding-Wheels, the centre line of the pivoted arm lying slightly off the axis of the driving cord; means for adjusting the arm about its pvot; and means for actuating the driving cord and cause the rotation of the grinding-Wheels, all substantially as and for the purpose set forth. u

LEONHARD KELLENBERGER. 

